Markets just got a hard lesson in humility, Jim Grant says

It's time for financial markets across the globe to eat a big slice of humble pie, Jim Grant said Friday after the shocking result from the United Kingdom referendum on European Union membership.

"It's a great day for humility," Grant, the founder and editor of Grant's Interest Rate Observer, told CNBC's "Squawk Box. "

Financial markets across the globe tumbled after the U.K. voted in favor of leaving the EU, a decision markets were not expecting. Ahead of the vote, several polls and bookmakers showed support leaning toward the remain camp.

On Friday, U.S. stock futures implied a lower open of more 2.5 percent, while major European indexes shed more than 4 to 8 percent.

Jim Grant

Chris Goodney | Bloomberg | Getty Images

"I've thought for some time that markets were anesthetized by central banks, and they've lost a little bit of their capacity to look into the future," Grant said. "What was so striking about the events of the past week is the fact that markets were just flat wrong."

"Markets, proverbially, were able to see through things that individuals were not and markets were absolutely wrong on this," he said.